Your calculation is okay, waseem. I think Wooferhound forgot to carry a "2".
I tried looking for information about this motor on the Baumuller website, but no luck. It may be a discontinued model or a motor made for a specific customer (not general purpose).
I guess with 300 RPM you could try a 3-blade turbine rotor about 2 meters in diameter. Running a little faster than necessary, it may be hard on plastic PVC blades, meaning they may not last very long.
I also assume that when you try to turn the shaft yourself, you can feel a step-step-step rotation which is common to DC motors. This will resist turning the blades until the wind has become fairly strong.
My best guess is that a wind turbine made from this motor will function, but in weak winds it will not turn at all, and in strong winds it will turn rather fast. If you use plastic blades it will be noisy and they may not last very long either.
If you want to find a different motor, you should try to aim for one that operates at a slower speed. If it were a 155V motor that turns at 2000 RPM, it would be excellent. If its working voltage is 100, then its working speed should be 1200 RPM.
